A wideband compensation stack film comprises a chiral-half-wave compensation film and a chiral-quarter-wave compensation film. The chiral-quarter-wave compensation film is directly in contact with the chiral half-wave compensation film. Along the contact surface, the first layer liquid crystal molecule of the chiral-quarter-wave compensation film is arranged in the last layer of liquid crystal molecule of the chiral-half-wave compensation film. The retardation values (R) and the optical axis (Z) of the stack films follow a linear relationship: R=aZ+b.